Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds real value beyond that: it discloses the empty-result state and the newsUrl fallback page where future events are announced, which an agent cannot infer from the schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the resource and scope, then the empty-state caveat. Every clause carries information; nothing repeats the title or name.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return-value detail is optional, and the description nonetheless names the article and .ics payload plus the empty case. Complete enough to call correctly; only the effect of 'limit' stays implicit.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the single 'limit' parameter carries its own description and bounds, so the schema does the work. The description says nothing about the limit or default page size, so it adds no meaning beyond the structured field.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb + resource ('Liste les prochains événements') and enumerates the covered event types (ateliers, webinaires, conférences) plus what each entry carries (article de présentation, fichier .ics). No sibling tool overlaps this scope, so no differentiation burden exists.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The trigger context is clear: the tool answers questions about upcoming Elfy.Life events. It also tells the agent what to do when the list is empty (point the user to newsUrl). No explicit exclusions or named alternatives, but none of the siblings are plausibly confusable.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.